apparmor/kernel-patches/for-mainline/d_path_namespace_root.diff

Index: linux-2.6/fs/dcache.c
===================================================================
--- linux-2.6.orig/fs/dcache.c
+++ linux-2.6/fs/dcache.c
@@ -1741,10 +1741,12 @@ shouldnt_be_hashed:
  * @buflen: buffer length
  * @flags: flags indicating what should be in the path
  *
- * Convert a dentry into an ASCII path name. If the entry has been deleted
- * and the DPATH_DELETED flag is set the string " (deleted)" is appended.
- * Note that this is ambiguous.
- *
+ * Convert a dentry into an ASCII path name.
+ * If the entry has been deleted and the DPATH_DELETED flag is set the
+ * string " (deleted)" is appended. Note that this is ambiguous.
+ * If the DPATH_NSROOT flag is set the path returned will walk past the
+ * chroot.
+ * 
  * Returns the buffer or an error code if the path was too long.
  *
  * "buflen" should be positive. Caller holds the dcache_lock.
@@ -1777,7 +1779,8 @@ static char * __d_path( struct dentry *d
 	for (;;) {
 		struct dentry * parent;
 
-		if (dentry == root && vfsmnt == rootmnt)
+		if (!(flags & DPATH_NSROOT) &&
+		    dentry == root && vfsmnt == rootmnt)
 			break;
 		if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
 			/* Global root? */
@@ -1823,18 +1826,22 @@ char * d_path_flags(struct dentry *dentr
 		    char *buf, int buflen, unsigned int flags)
 {
 	char *res;
-	struct vfsmount *rootmnt;
-	struct dentry *root;
+	struct vfsmount *rootmnt = NULL;
+	struct dentry *root = NULL;
 
-	read_lock(&current->fs->lock);
-	rootmnt = mntget(current->fs->rootmnt);
-	root = dget(current->fs->root);
-	read_unlock(&current->fs->lock);
+	if (!(flags & DPATH_NSROOT)) {
+		read_lock(&current->fs->lock);
+		rootmnt = mntget(current->fs->rootmnt);
+		root = dget(current->fs->root);
+		read_unlock(&current->fs->lock);
+	}
 	spin_lock(&dcache_lock);
 	res = __d_path(dentry, vfsmnt, root, rootmnt, buf, buflen, flags);
 	spin_unlock(&dcache_lock);
-	dput(root);
-	mntput(rootmnt);
+	if (!(flags & DPATH_NSROOT)) {
+		dput(root);
+		mntput(rootmnt);
+	}
 	return res;
 }
 
Index: linux-2.6/include/linux/dcache.h
===================================================================
--- linux-2.6.orig/include/linux/dcache.h
+++ linux-2.6/include/linux/dcache.h
@@ -178,6 +178,7 @@ d_iput:		no		no		no       yes
 
 /* d_path flags */
 #define DPATH_DELETED		0x0001	/* append " (deleted)" */
+#define DPATH_NSROOT		0x0002	/* continue past fsroot (chroot) */
 
 extern spinlock_t dcache_lock;